127 Australian lizard and snake species at risk — a ‘conservation gap’ larger than official lists suggest

A nationwide review suggests that the scale of the crisis facing Australian lizards and snakes may be greater than official lists indicate. By combining lists from various jurisdictions with new empirical data and predictive models, researchers found that at least 127 species of terrestrial squamates—representing 13.1% of assessable species—are potentially threatened. This is nearly double the 7.1% figure from the 2017 national assessment.

However, this does not mean the number of threatened species suddenly doubled in eight years. The review, released in August 2026, reflects newly named species, improved data on distribution and threats, and discrepancies between agency lists. The key message is not just that the risk has grown, but that the pace of officially recognizing these risks and implementing recovery initiatives is failing to keep up.

30-Second Summary

• Twenty-three Australian reptile experts reviewed progress made since the 2017 action plan.
• At least 127 species—13.1% of assessable terrestrial lizards and snakes—are potentially threatened.
• Species with insufficient data were 5.4 times more likely to be threatened than those with adequate data.
• Of the 127 species, 71 appear on the IUCN list and 70 on the Australian federal list, with only 48 appearing on both.
• Researchers urged investment in taxonomy, monitoring, and recovery programs ahead of the 2027 reassessment.

What happened?

The study ‘Conserving Australian lizards and snakes: an update on progress since 2017,’ published in *Pacific Conservation Biology*, reviews the implementation status—as of late 2025—of the six recommendations outlined in the 2017 Action Plan for Australian Lizards and Snakes. Researchers evaluated the IUCN Red List, federal, state, and territory lists alongside new field data and predictive models, ultimately proposing 11 recommendations to improve conservation efforts.

Information Subject to Review

Subject	Australian terrestrial lizards and snakes (Squamata)
Classification	“Class Reptilia, Order Squamata
Distribution	Tropical, arid, semi-arid, and temperate ecosystems across Australia
Endemism	Approximately 98% of Australian squamates are endemic to Australia
Exclusions	Sea snakes and freshwater turtles excluded from this review
Conservation Status	Discrepancies between IUCN, federal, and state/territory lists and the research team’s integrated assessment

How the 127 species were calculated

The 2017 IUCN assessment covered 986 of the 990 Australian squamate species recognized at the time. This study incorporated subsequently identified taxa and new data, combining species recognized as threatened across various jurisdictions with those not yet on official lists but showing high risk in empirical data or models. This resulted in a figure of 127 species—representing 13.1% of the species for which sufficient data existed to calculate a proportion.

The lack of data itself was a warning sign. Species classified as ‘Data Deficient’ were 5.4 times more likely to be threatened than those with sufficient data, while ‘Not Evaluated’ species were 3 times more likely. Between 2017 and 2025, the number of recognized terrestrial lizard and snake species rose from 955 to 1,066. As of August 2025, among the 115 species that had not yet undergone a conservation assessment, approximately 25 were estimated to be potentially threatened based on modeling.

Threats overlap

The extent of the massive Australian bushfires in 2019–2020 overlapped with the distribution ranges of 445 lizard and snake species. While some populations of wide-ranging species might survive, species restricted to mountaintops or small rainforest fragments could lose most of their habitat in a single major fire. Other factors—such as climate change, grazing by livestock and feral herbivores, hotter fires fueled by invasive buffelgrass, and predation by cats and foxes—are also at play simultaneously.

Discrepancies between official lists also delay actual interventions. Among the 127 species identified by the research team, 71 were classified as threatened by the IUCN and 70 by the Australian federal list, yet only 48 species appeared on both. Listing a species is merely a starting point; long-term monitoring and a recovery plan backed by a budget must follow to track changes in population size.

Why is this important?

Australia is home to approximately 10% of the world’s lizard and snake species, with about 98% of them found nowhere else. Consequently, the disappearance of a species from Australia is highly likely to result in global extinction. Researchers have proposed reversing the decline in taxonomic and museum expertise and simultaneously pursuing targeted surveys for data-deficient species, long-term population monitoring, Indigenous-led management, and—where necessary—conservation breeding and planned translocation.

Points to avoid overinterpreting

The 13.1% figure does not represent a population decline rate derived from new field surveys conducted identically across all 1,066 species. Rather, it is the result of a review that integrated various lists, studies, and models to calculate the proportion of species at high risk of threat. When making a simple comparison with the 7.1% figure from 2017, one must account for the effects of new species descriptions and improved data availability. Furthermore, discrepancies between the IUCN list and the federal list do not imply that either is entirely incorrect; these differences arise from variations in assessment timing, legal criteria, and the speed of data updates.

Study limitations and remaining questions

The finding that species with the least data may face the highest actual risk paradoxically implies a high level of uncertainty. Species identified by predictive models require verification through targeted field surveys. For the nationwide reassessment scheduled for 2027, it is necessary to incorporate citizen science data more systematically and compare status changes across 1993, 2017, and 2027 to determine whether conservation measures have led to actual recovery.

Key takeaways for readers

1. At least 127 species of Australian terrestrial lizards and snakes may be at risk.
2. A lack of data does not imply safety; it could signal a greater risk.
3. Discrepancies between IUCN, federal, and state lists create gaps in conservation.
4. Wildfires, climate change, invasive species, and habitat alterations amplify one another.
5. The key to the 2027 reassessment is linking list updates to actual monitoring and recovery initiatives.

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Original source, DOI, and references

• Chapple et al. (2026), *Pacific Conservation Biology* original paper — DOI 10.1071/PC25096
• ConnectSci·CSIRO Publishing original article page
• Monash Lens researcher commentary, August 27, 2026
• Australian Government Common Assessment Method